1. Field of the Invention
This invention relates to a connector having a female housing and a male housing that is inserted and fitted into the female housing, and in particular to a connector having an improved locking structure which improves the fitting force between the female and male housings.
2. Description of the Prior Art
Generally, as shown in FIG. 1, a conventional connector 1 comprises a female housing 3 and a male housing 5 to be fitted into the female housing 3. In the female housing 3 there are provided a plurality of terminal accommodating compartments 9 in which the female terminals connected to wires are accommodated, respectively. Similarly, in the male housing 5 there are provided a plurality of male terminal accommodating compartments (not shown) in which male terminals (not shown) are accommodated, respectively, so as to make electrical contact with the female terminals when the female and male housing are fitted together.
On the upper surface of the outer wall 3a of the female housing 3, there is formed a U-shaped notch 10 which extends toward the insertion direction of the male housing 5. Further, on the upper surface of the outer wall 3a of the female housing 3, a locking arm 11 is provided. The locking arm 11 is a substantially C-shaped member having two leg portions 11a and a locking portion 11b integrally formed between the leg portions 11a. The locking arm 11 is provided so as to protrude over the notch 10 by attaching the tip portions of the leg portions 11a onto the upper surface 3a of the female housing 3. With this configuration, the locking arm 11 has a locking aperture 11c defined by the leg portions 11a and the locking portion 11b. Further, the locking arm 11 is flexibly supported to the female housing 3 at the tip portions of the leg portions 11a.
On the upper surface 5a of the outer wall of the male housing 5, there is formed a locking projection 13 to be locked with the locking aperture 11c of the locking arm 11 when the female and male housings 3, 5 are fitted together. As can be seen in FIG. 2, the locking projection 13 has a substantially triangular shape in cross section; that is, a first inclined surface 13a that declines toward the insertion direction of the male housing 5, a second inclined surface 13b that declines toward the opposite direction and a vertical surface 13c. The vertical surface 13c of the locking projection 13 engages with the inside surface of the locking portion 11b of the locking arm 11 when the female and male housings 3, 5 are properly fitted together.
Namely, when the male housing 5 is inserted into the female housing 3, the outer edge 11d of the locking edge portion 11b is abutted on the first inclined surface 13a of the locking projection 13. Then, the locking edge portion 11c is gradually lifted along the inclined surface 13a as the male housing 5 is inserted into the female housing 3, which causes the locking arm 11 to become cambered, thereby generating a restoring force within the locking arm 11. After the locking edge portion 11b of the locking arm 11 crosses the peak 13d of the projection 13, the locking edge portion 11c is suddenly lowered along the second inclined 13b due to the restoring force in the locking arm 11. Thereafter, as shown in FIGS. 2 and 3, the inside surface 11e of the locking edge portion is in engagement with the vertical surface 13c of the locking projection 13. Such an engagement occurs when the male housing 5 is perfectly fitted to the female housing 3.
However, in this conventional connector, the restoring force in the locking arm may be insufficient to attain a perfect locking condition with the locking projection, and thus an imperfect fitting may occur between the male housing 5 and the female housing 3. This leads to disadvantages such as poor electrical connection in the connector and increased chances that the housings may come apart.
In order to overcome the disadvantages of the conventional connector, one might simply conceive of increasing the restoring force in the locking arm. However, this would make it more difficult to remove the fitted housings from each other due to the extra force required to disengage the locking arm from the locking projection.